#pragma once
#include "bieuthuc.h"
class BieuThucHang :
	public BieuThuc
{
private:
	double hangSo;
	BieuThucHang();
	BieuThucHang(double hangSo);
	static BieuThucHang* ZERO;
public:
	static BieuThucHang* taoBieuThucHang(double hangSo);
	virtual double tinhGiaTri(double x);
	//virtual BieuThuc* tinhDaoHam();
	virtual BieuThuc* timDaoHam();
	virtual void daoDauBieuThuc();
	virtual string xuatChuoi();
};

